Visualization of Gap Junction-Mediated Astrocyte Coupling in Acute Mouse Brain Slices

Area of Science:

• Neuroscience
• Cell Biology
• Biophysics

Background:

• Gap junctions facilitate intercellular communication via small molecule exchange, crucial for central nervous system (CNS) homeostasis.
• Panglial networks, formed by coupled glial cells in the CNS, play a vital role in maintaining brain function.
• Visualizing cell-to-cell coupling in situ typically involves tracer diffusion across gap junctions.

Purpose of the Study:

• To describe a protocol for pre-labeling and identifying astrocytes in acute mouse forebrain slices.
• To enable visualization and analysis of dye-coupled astrocytic networks.
• To provide a method adaptable for other glial cell types, tissues, and species.

Main Methods:

• Pre-labeling of live astrocytes in acute adult mouse brain slices using Sulforhodamine 101 (SR101).
• Whole-cell patch-clamp electrophysiology for astrocyte identification and biocytin dialysis.
• Post-fixation staining of biocytin with streptavidin and GFAP immunostaining for network visualization.

Main Results:

• Successful identification of live astrocytes in brain slices using SR101 fluorescence.
• Demonstration of biocytin dialysis for assessing electrophysiological properties and coupling.
• Visualization of dye-coupled astrocytic networks through subsequent staining and imaging.

Conclusions:

• The SR101 labeling and patch-clamp protocol effectively identifies astrocytes in live tissue.
• This method allows for detailed analysis of astrocytic networks and intercellular communication.
• The protocol's adaptability makes it valuable for studying diverse glial cell interactions across species.